I have had
a chance to study your three 1995 papers with Jeffrey Gray, Glenn Wilson
et al. We have a great deal to talk about on the topics of Eysenck's
Arousal/Activation, Gray's BIS/BAS and the Cartesian Theory. Much of this
discussion is detailed, specific and experimentally based and involves
much experimental data from the literature. It is reported
that when Freud first met Jung they talked for 14 hours; I have the
feeling that we could easily duplicate that... but obviously not in a single
letter!

So, rather
than write you a lengthy communication; launching right into a discussion
of how the Cartesian Theory explains Arousal/Activation, identifies Gray's
BIS/BAS as the two lateralized halves of the SHS and reconciles Eysenck's
and Gray's biological models etc., I have decided that it would be more
to the point to answer the few essential points you have raised in your
letter of October 18th.

First, let
me underscore and emphasize most strongly, that it is precisely an understanding
and comprehension of this point that is the sine qua non of the entire
Cartesian Theory! Furthermore, it is precisely an understanding of
this point that, in general, is preventing Psychology from comprehending
the Cartesian Theory. I have briefly discussed this matter with Hans
Eysenck himself in Montreal, and its clear that he doesn't understand it;
to wit, when I tried to impress on him the axiomatic nature of the fact
that E, N and P originate biologically in the first 3 cleavages of the
egg (cf. Roux 1888; Conklin 05, 06) he said to me: "I don't see the
relevance of it." Well, unfortunately I was so sick and exhausted
by the time I reached Montreal that I wasn't able to respond adequately
with something like; "it demonstrates that E,N,P have biological parity."
or some such technically concise answer. Anyway, upon subsequent
reflection, I'm rather glad that our meeting remained rather on the personal
wavelength than on the technical; because I don't think it proper in the
first place for someone like me to be engaging someone like Hans Eysenck
on the technical/argumentative level... I think its more appropriate that
other technical experts take a look at it and form an opinion first.
That's where I think someone like you comes in, because apparently you
are an experimentalist. I notice that your Ph.D. thesis was on an
investigation of the biological bases of the Structural Model of Personality.
Such a topic could not be more appropriate to this discussion. I
have only discussed this theory at length with one other person, Paul Barrett,
and despite his association with the Biosignal Laboratory he strikes me
as more committed to psychometric questions than experimental. At any rate,
here we are, and I would like to see if it is possible to explain to you
"why real Cartesian space causes psychometric Cartesian space". the first
thing I notice is that in your statement (quoted above) you do allow as
how the "gross morphological features" of the vertebrate body and brain
are apparently 3-axis Cartesian. At least that's my reading of your
statement; when you say "Apart from gross morphological features, ..?".
I interpret this to mean that while you do allow as how the "gross morphological
features" of the brain appear to be de facto 3-axis Cartesian... your question
really is; why should Psychometry be 3-axis Cartesian as a general stand
alone scientific rule in its own right? I gather at least, that that
is your question. Well, let
me insist that there is an answer to this question and that the trouble
lies in the fact that the answer derives from (theoretical) Physics and
not from (empirical) Psychology; that's the problem! The "simple"
answer to the question is this: That the "gross morphological features"
of the vertebrate body and CNS are not simply de facto 3-axis Cartesian;
they are axiomatically 3-axis Cartesian. There is a world of difference
between "de facto" and "axiomatic". O.k., so
let me dispose of this "axiomatic issue" before I get into the micro-mechanics
of how, phenomenologically, Cartesian space causes Cartesian psychological
space. This latter discussion I'm sure you'll find more interesting;
probably being better versed in "Natural Science" while the former "axiomatic
question" involves axiomatic science, that is, Theoretical Physics. Anyway, taking
up the "axiomatic" issue first: There is a fundamental law of Physics
(wch. is not something we would expect Psychologists to be generally aware
of) that may be paraphrased as follows:

Any machine
designed to freely operate in (or span)
N-dimensional space, must have a minimum of N orthogonal
mechanical axes of structure (i.e. must have N mechanical
degrees of freedom).

Now, for the human
body, N=3 (three dimensions), because we are designed to operate in (or
fully span) 3-dimensional space. A typewriter
and T.V. are examples of N=2 (scroll and carriage return; horizontal and
vertical hold). An airplane has N=3 (pitch, roll and yaw), and so
does the vertebrate body (the 3 semicircular canals detectpitch, roll and
yaw along the 3-cartesian body axes in the human); Figure 1.

Now since
is an "axiomatic law" of classical mechanics, we see that the "3-mechanical
axes" of the human body are not accidental, fortuitous or de facto... no,
they are preordained by an axiomatic mechanical law from classical Physics.
the body must have 3-orthogonal mechanical axes, no less than 3, no more
than 3, and precisely 3. This is a primary law of Physics and it
can be accurately said that it is a law of Physics that "man is created
in the image of the Cartesian coordinate system". All right,
so much for the elementary mechanical structure of the human body; it's
axiomatic, but how do we get from there to the psychometric structure of
man? That turns out to be a very interesting Natural Science story;
the story I shall embark on next.

As I have
pointed out, a fish, is the simplest example of this (now axiomatic) 3-axis
biological structure, but it turns out that the "generalized vertebrate
body plan" clearly manifests this structure (Fig. 2):

In this diagram
we see the medial, lateral and transverse septums defining these 3-Cartesian
axes in the gross anatomical structure of the vertebrate animal.
Note that the hypaxial and epaxial muscles (esp. in a fish) clearly highlight
the "axial quadrature" of the vertebrate body plan. So the primitive
vertebrate body plan may be reduced to a simple 3-axis diagram thus (Fig.
3):

Now, so far
we haven't said anything about the nervous system, and in order to do so
we have to survey the entire evolutionary history of zoology (I will attempt
to do this in a few paragraphs). all animals
begin as a single cell, the egg. This egg, itself, has a 3-axis Cartesian
structure. You can in other words, draw a 3-axis "Cartesian homunculus"
right inside the egg itself with the head at the "animal pole" and the
feet at the "vegetal pole" (Fig. 4):

The egg begins
expressing this body structure through "binary Cartesian cell division"
and the first 3-cleavages are precisely along the 3 body axes of the homunculus
x,y,z in Fig. 4. Shown in
Fig. 5 are the first 3 orthogonal (Cartesian) cleavages; producing the
2,4 and 8 cell stages of the embryo.

Fig. 5 (above)

Now next,
I am about to describe one of the most important scientific discoveries
in the history of biology, namely Wilhelm Roux's celebrated discovery of
1888. This experiment rocked the scientific world and earned Roux
the title of "Father of Modern Embryology". Roux was watching a frog's
egg collected from a local pond with a magnifying glass. He observed
it make the first cleavage to the 2 cell stage. On what impulse Heaven
only knows, he took a common pin and heated it in the candle flame and
stuck one of the cells... pssst! He then let the thing continue to
cleave and grow. The result was astonishing... it grew into half
a frog! Only the right half of the tadpole emerged.. the left half
was entirely missing. Roux had discovered that the first cell cleavage
of life produces the bilateral symmetry line of the human body (including
notably the medial fissure of the brain). Conklin in
1905, 06 continuing this research on Styela also confirmed that if you
separate the front two cells from the back two in the 4 cell stage (dorso-ventral
separation instead of left-right separation) you will produce 2 "half embryos",
only this time a front half and a back half! A sketch of all this
is shown in Fig 6.

Now what does this
prove? It proves that the vertebrate body is "theoretically" an axial
quadrature which is isomorphic with the first 3 Cartesian cleavages of
the egg. It shows that the first 3 cleavages of the egg are isomorphic
with the 3 Cartesian axes of the "generalized vertebrate body plan" shown
in Fig. 2. In particular
it shows that the Sperrian and Bell-Magendian divisions of the brain derive
from the same elementary biological mechanism- namely the first and second
orthogonal Cartesian cleavages of the egg.

Now, leaving
embryology for a minute, we have to turn to zoological evolution; mainly
to elucidate the history of the geometric origin (structure) of the CNS. The most
primitive animals (sessile animals) only display clear Cartesian structure
in the early Cartesian-binary formative stages of embryology (which we
have been discussing above). Until they are subject to the Cartesian
dynamics of movement (moving animals), this initial Cartesian influence
on body form may peter out as the animal gets larger.. but it is evident
even in such primitive sessile animals as the Hydra or certainly in bivalves
(clams). However, once we proceed up the evolutionary chain to moving
animals, the Cartesian axiom takes over and transforms the original formative
Cartesian structure (wch. in itself is a static formative Cartesian necessity;
probably deriving from molecular Cartesian structure bonding structure
itself; the p-orbitals are Cartesian) and Cartesian structure is reimposed
on the macroscopic "gross anatomy" form of the body itself. A longitudinal
axis develops first and immediately thereafter bilateral symmetry appears.
By the time we get up into the cephalopods, chordates and vertebrates,
the 3-axis macroscopic body form is fully established (Fig. 2). O.k. so we
have seen that 3-axis Cartesian structure is used in the formative stage
of all animals and is continued directly up to the gross anatomy
stage in moving animals... manifesting its most fully expressed degree
in the vertebrates. On the subject
of moving animals, quite a bit more has to be said vis a vis 3-axis Cartesian
structure... wch. I will only briefly outline here. Moving animals
immediately adopt a "longitudinal" body plan. While a sponge or a
jellyfish may simply be a blob, a worm, a fish, and insect or any animal
engaged in active travel, immediately adopts a "lengthwise" body plan with
the body axis pointing in the direction of motion and with the head and
mouth at the front and the aboral end at the back. This "travel"
axis corresponds to the "z-axis" in the egg (cf. Fig. 4). O.k. so
we now have a bilateral, longitudinal, prone animal. The only axis
left of the 3 is the dorso-ventral axis, which now corresponds to the top
and bottom (back and belly) of the animal. This is now coincident
with the up vs. down direction in the terrestrial Cartesian coordinate
frame of reference. The 3-body axes have now permanently aligned
themselves with the "horizontal, vertical and forwards-backwards" axes
of the terrestrial environment. This body axis orientation first
becomes firmly established in the Cambrian invertebrates, chordates (primitive
fishes), insects, vertebrates and finally the tetrapod vertebrates (4 legged
animals, including man). Alright,
we have seen the axiomatic origin of the 3-axis Cartesian vertebrate body
plan, and we have seen the evolutionary orientation of the 3 body axes
to the 3 terrestrial Cartesian axes of the environment. This process
has created the physical, geometric, appearance of the higher tetrapod
life forms e.g. a cow, a horse or a dog. From there to man, with
the well known 90 degree rotation of the longitudinal axis for bipedal
gait is simply a trivial final step in this 4-billion year saga. But we have
yet to mention the geometry of the CNS... where does the structure of the
nervous system enter into the evolutionary picture? The main
purpose of the nervous system is the motor-sensory reflex. This reflex
predates even the evolution of the neuron. An Amoeba exhibits motor-sensory
reflex- if you touch it, it moves away, and yet, there isn't a single nerve
cell in an Amoeba! A study of
zoological evolution shows, first, the development of motor nerves, especially
in connection with locomotion. Fig. 7 shows an elementary invertebrate
animal with both legs and eyes.

This simple animal
has a ventral nerve cord (called the "pedal" nerve cord) wch. consists
of motor nerves controlling the legs. Dorsally, the eyes are connected
o two (bilateral) sensory ganglia. The pedal nerve cord is connected
to two "motor ganglia".. These 4 motor-sensory ganglia are connected
in a ring surrounding the esohoogus. Here we already see a dorso-ventral
separation of the motor and sensory nerves; simply because the legs are
ventral and the eyes are dorsal. Obviously we can attribute this
dorso-ventral geometry to the fact that the D-V body axis is aligned with
gravity and causes the legs only to appear on the ventral side of the body. Now, as animals
get more advanced they start developing sensory nerves, as well as motor
nerves, connecting the muscles to the brain. A Lamprey for instance
(a primitive jawless fish still extant) has a full blown "spinal cord"
consisting of motor and sensory nerves situated now dorso-ventrally (Fig
8):

Fig.8 (above)

Now, with
the ever increasing number of nerves and a concomitant increasing "cephalization"
of the CNS in the evolution of animals; the next thing that appears out
of necessity, is a body/brain map or neurological homunculus in the brain,
in order to organize and coordinate these thousands or millions of nerves. The first
requirement of this homunculus is that it must be "mirror symmetric" between
the motor and sensory maps; this because the most elementary m-s action
is the reflex, i.e. a mirror symmetric motor-sensory reaction. Now, all
I can do in this letter is touch on the highlights, less the thing become
a book! It encompasses 15 years of study. So allow me to present
a somewhat heuristic/illustrative description of how the vertebrate "motor-sensory
homunculus" of the cortex came into being. It stems
originally from the fact that the "neural tube" (embryological spinal cord)
itself derives its structure; like the other axial tubes of the body (alimentary
canal and spinal column)- directly from the 4-cell stage. The reason
that the spinal column and the neural tube manifest 3-axis geometrical
symmetry, is because they are homologous with the first and second cleavages
of the egg. The crossection of the neural tube is shown in its relation
to the 4-cell stage in fig. 9:

So the 2-axis
mirror symmetric substrate of the neural tube derives from the first two
mirror symmetric cleavages in embryology. I will spare you the details
of involution, gastrulation and generation of the neural tube in embryology,
other than to cite a classic paper in the field in which vital stain (dye)
was injected into the 4-cell stage and traced all the way to the 4-quadrants
of the crossection of the neural tube; demonstrating conclusively this
Cartesian morphology (Hirose & Jacobsen 1979). At any rate,
the CNS in embryology begins as the neural tube which is 3-axis Cartesian,
Fig. 10:

These 3-axes
are shown above. The alar plate and the basal plate, are also known
as the sensory and motor plates because the crossection of the neural tube
shown in Fig. 10 becomes the familiar "butterfly" crossection of the adult
spinal cord in wch. the ventral half is motor and the dorsal half sensory
Fig. 11:

Also shown
in Fig.11 is the Telencephalic end of the neural tube (CNS) in the adult.
Here we see the "butterfly" has turned into the full blown mirror symmetric
m-s "map" that we mentioned earlier. Now this map is taken directly
from Gray's Anatomy (38th edition, p. 1155, Fig. 8.260) and
is experimentally accurate. The two maps are mirror symmetric across
the Medial and Central fissures of the brain. The Central fissure
corresponds morphogenicall to the Sulcus Limitans in the neural tube.
The 2 images are "face to face" symmetric across the Central fissure. Now, we are
concerned here with how and why this mirror symmetric map came into being
and why it is astride the Medial and Central fissures of the brain and
how this is related to the fundamental Cartesian geometry of the vertebrate
body. The basic question is: what has motor-sensory function
got to do with Cartesian geometry? Particularly; what has it got
to do with the embryological formative Cartesian geometry of the CNS neural
tube? Well, there
is an answer to this question and you won't find it in a book; I have had
to discover it! We have the following facts:

1. The esophagus,
spinal column and neural tube are all morphologically 3-axis Cartesian
and derive this geometry from the 3-axis Cartesian structure of the first
3-cleavages of the egg.

2. The question
then is basically this- why would the motor-sensory function decide to
take up residence in a dorso-ventral position in this tube with the motor
legs pointing "foot to foot" with the sensory legs in the m-s homunculus;
as we see in Fig. 11?

Well, the
answer to this derives form the evolutionary history of the animal, and
in particular to the fact that we have already mentioned, that in evolution
the 3-ontogenetic body axes become "oriented" to the 3-terrestrial Cartesian
axes (horizontal, vertical and forwards-backwards). Of particular
significance is that (in "prone" animals) the dorso-ventral axis is aligned
with the gravity axis, Fig. 12:

Now, the significance
of this, is that the legs of the animal appear only on the ventral side;
to support it against gravity (Fig. 12). These legs are positioned
in the L-R ventral quadrants of the vertebrate body plan. This is
a dorso-ventral asymmetry imposed on the body by the unidirectional force
of gravity. Gravity is the principal and largest geometric asymmetry
in the terrestrial Cartesian coordinate system. Now the brain
and the body, as we have seen, is an ontogenetic axial quadrature.
Now, therefore, the simplest structural scheme for connecting the brain
to the body, is a direct 1 to 1 (isomorphic) correspondence, Fig. 13:

Now, in this
diagram I have drawn a hypothetical animal with symmetric dorsal and ventral
legs; in order to preserve the "axially symmetric vertebrate body plan".
In this scheme the 4-quadrants of the brain controlling these 4-legs are
supposed to be entirely motor... this is a simple "open loop" animal with
no sensory nervous system. This might correspond to a simple eyeless
primitive invertebrate with a 4-way "pedal nerve cord" mentioned earlier. Now this
model although theoretically simple does not correspond to reality because
we have 2 facts to deal with:

1. Legs are only
ventral because of gravity.

2. The CNS of higher
animals is a reflex system with both motor and sensory nerves.

As we will now see,
the simple "theoretical" model of Fig. 13 is exactly suited to accommodate
these 2 facts. The reason is this; unlike the theoretical animal
(Fig. 13), the real animal has only ventral legs- and this leaves the 2
dorsal quadrants of the brain with nothing to do. However, this is
where the matter of the "reflex" system comes in; Fig. 14:

Here we have an
actual animal with only ventral legs (horse, dog, cat etc.). These
legs support the animal against gravity for the purpose of locomotion.
Now the sensory nerves in the legs sense the force of gravity and the motor
nerves cause an equal and opposite force so that the animal remains in
equilibrium (i.e. "stands"). Now, one
way to visualize this, is that the animal is walking on a mirror, and there
is a "gravity reflexion" animal walking against it "foot to foot" (Fig.
14). The nerve output of this "gravity reflexion" animal would be
exactly equal to the sensory nervous output in the legs of the actual animal!
So, biologically speaking, the force of gravity has turned our "ventral
legs only" animal into an animal that "thinks" it has both dorsal and ventral
symmetric legs because of gravity and the existence of both motor and sensory
nerves. Now,
as we have seen, the two hypothetical dorsal legs of the "theoretical symmetric
animal" are actually missing, but the body "knows" that they could exist
because of symmetry (note that in a fly, Fig. 13, all 4 quadrants are used;
the wings becoming the "dorsal legs")... but now because of gravity and
sensory nerves, it HAS two mirror symmetric legs that it has to place somewhere
in the brain. Obviously it simply places these two sensory (and now
gravity reflex) legs in the two empty dorsal quadrants of the brain.
Thus it is, that the Bell-Magendie symmetry map, or motor-sensory homunculus
of the cortex comes into being ( Fig. 15). Note that the "dorsal
and ventral" rami of the (mised motor and sensory) spinal nerves still
serve the original 4-axial Cartesian quadrants of the body; with the ventral
rami controlling the legs.

O.k., so what
does all of this tell us? Well, the first thing it tells us is that
the Bell-Magendie symmetry and the L-R Sperrian symmetry are NOT UNRELATED.
In fact, what it tells us is that they stem from an absolute structural/mechanical
equivalence. They have biological equivalence because they (structurally)
originate in primary cleavages of the egg (namely the 1st and 2nd primary
orthogonal cleavages). They have mechanical (functional) equivalence
because they both originate in a transverse structural/mechanical mirror
symmetry due to the legs (L-R and D-V). They are certainly NOT two
disparate and unrelated neurological systems.

O.k. then,
we are still on the road to answering your original question:

"Why would the Cartesian
structure of space cause a Cartesian structure of psychometry in Personality."

We have certainly
come a long way. We have in fact started with the Cartesian structure
of space, seen how it dictates the Cartesian mechanical structure of the
body (the Cartesian axiom) and then proceeded through zoological evolution
and embryology to see how this causes the B/M and Sperrian symmetries (and
the neuraxial cephalization gradient too). We are now therefore on
the doorstep of modern experimental and psychometric research in Personality
psychology. The foregoing
exposition has shown, clearly, how the Cartesian structure of the body
has caused the B/M and Sperrian symmetries. To complete the answer
to your question then, I simply assert that modern psychology research
shows that the B/M and Sperrian dichotomies cause Eysenck's E and N Personality
dimensions. If this can be shown, we have an unbroken chain of causality
from the "Cartesian structure of the brain to the Cartesian structure of
Psychology". Indeed, from the Cartesian structure of real space to
the Cartesian structure of Personality space! A truly historic scientific
revelation. Now, the
evidence connecting B/M and Sperry to E and N lies squarely in modern psychology
research and gets us immediately into your research on Arousal and Activation. As far as
the E dimension goes, the argument runs as follows: Eysenck's Arousal
thesis is known to have substantial experimental validity as a neuropsychological
explanation of E-I. Basically Introverts are more Aroused than Extraverts.
However, as Eysenck points out, there is still a fundamental ambiguity
in the Arousal Hypothesis; he says:

"Furthermore, there
are two possibilities concerning Arousal differences. It is possible
that introverts are more sensitive to incoming stimuli and become more
aroused as a result of stimulation; or they may have high tonic arousal
anyway, and their response ... may reflect this basic arousal difference."
Eysenck, in Handbook of Personality
Ch. 10, p. 259; Guilford Press, 1990

This suspicion is
testified to by the fact that many researchers, ignoring Arousal theory,
simply state without qualification that:

"Introverts are
more sensitive to sensory stimulation than Extraverts".

(cf. Powell,
Gray, Claridge etc.)

Eysenck cites
particularly Stelmack's research in this connection (1990 p. 252) where
he says:

"As they point out,
these results provide some evidence of individual differences in physiological
responsiveness at the level of the auditory nerve and the brain stem.
The findings are not easy to explain in terms of a simple arousal theory,
and the authors (Stelmack & Wilson 1982) argue that their findings
may require the development of new conceptions of the neurophysiological
bases of individual differences in E ..."

Eysenck, (ibid 1990, p. 252)

A year later
Stelmack and Plouffe (1983) followed up on this discovery with a major
experimental thesis entitled:

Introversion-Extraversion:
The Bell-Magendie Law Revisited

(Stelmack & Plouffe 1983)

In this paper Stelmack
advances directly, based on experimental evidence that "the case can be
made" that E-I is caused by the Bell-Magendie dichotomy at the neurophysiological
level of the properties of the motor and sensory nerves. Anyway, I
take Stelmack's finding to be absolutely fundamental to the Cartesian Theory.
According to his research and the Cartesian Theory, what we see is that
Eysenck's "Arousal" is mainly "higher sensory sensitivity" which underlies
Introversion. At the other end of the scale, (and also according
to Stelmack) we see that Extraversion is caused by enhanced motor cortex
activity- thus the fully bipolar psychometric dimension of E-I. On the question
of N, as Eysenck states in his 1990 Chapter, there has been a lot less
work done on N and the experimental measurement of "Activation".
Given this, it seems more productive here for me to work backwards from
the Cartesian Theory to the experimental data rather than, as in the case
of E-I starting with the experiments (Stelmack) and working forward to
the Cartesian Theory. The main
reason for this is the following: According to the Cartesian Theory
N is caused by Sperrian Lateralization; the left-brain vs. the right-brain.
This is entirely similar to the situation for E-I which is caused by the
motor cortex vs. the sensory cortex (front brain vs back brain).
But this immediately tells us that "N" should be a major strong "bipolar"
psychological dimension like E-I. Extreme E or extreme I are pathological,
so that E-I has pathology at both ends and "normality" in the middle.
This is not so with Eysenck's N formulation (or P for that matter).
Eysenck's N has "above normal" on one end, pathology at he other end and
normal in the middle. This, if explained by Sperrian Lateralization
would tell us that the R-hemisphere is "above normal" and that the L-hemisphere
is neurotic. That's obviously ridiculous. No; what we immediately
see is that N should have pathology on both ends and normality in the middle
of the scale just like E-I. O.k., so
if this latter idea is true, what the heck is Eysenck's N really measuring?
Well, a little investigation soon produces an answer. First of all,
"emotionality" apparently is the principal psychometric marker of Sperrian
Lateralization in Personality. There undoubtedly are a lot of other
"Sperrian related features" in this second orthogonal dimension, but "emotionality"
seems to be the most immediately visible. What we suspect now however
is that there is "R-hemisphere emotion" and "L-hemisphere emotion" which
would, if properly assessed in a written questionnaire, produce a strong
bipolar Neuroticism scale with normal in the middle. Classic "Neurosis"
would still be where it is (since I surmise this is principally L-brain
emotionality). However, I think we are going to "rediscover" that
there exists R-brain emotion (basically Mania) which is going to be at
the opposite end of the scale. So o.k.,
what is Eysenck's-N measuring? Well, it's measuring |N|; i.e. "absolute
value of N". In other words Eysenck is measuring "absolute level
of emotionality" irrespective of whether its Left or Right (e.g. Manic
or Neurotic). Eysenck's N is the magnitude of a vector quantity!
Eysenck's N scale in other words, essentially folds the True-N scale in
half so that normality (non-pathology) which should be in the middle is
now at one end. Now I'm not
the first one to suspect this. The reverend Professor Leslie J. Francis
has actually empirically detected this in Eysenck's N-scales:

The dual Nature..............

(Francis 1993)

In this paper,
Francis has discovered the obvious, that women score higher on N than men
(note it is well known that men score higher on P, so this in itself is
not unprecedented). However, Francis has gone further, he has separated
out the sex (female) biased items from the non gender items in all of Eysenck's
tests, calling the first group NEUROS and the second group NEUROA (see
Francis 1993, p. xx). My interpretation
of these two scales is that NEUROS contains only classic Neurosis items
(e.g. loneliness, despair, hurt feelings etc.) while NEUROA contains items
descriptive of generalized emotionality that could occur on either the
right or the left (e.g. either manic or neurotic emotionality); such as
"fed up, annoyed etc.". Therefore NEUROS is measuring "True-N" (classic
Neurosis) and NEUROA is measuring Eysenck's |N| ("absolute" N). I
have proposed elsewhere that running a test of NEUROS and NEUROA along
with a simple written test to determine R-L brain preference (lateralization)
would show NEUROS to be significantly correlated with L-brain preference
and NEUROA to be correlated with "absolute magnitude" of lateralization
irregardless of left or right. Now, what
makes me so confident of all this? Well, first of all, it is already
established that Trait Anxiety (highly related to N) does correlate with
L-brain preference in exactly this kind of testing procedure (Tucker xx;
Tucker & Tyler xx). Moreover there is a large literature on the
Lateralization of Emotion (see Silberman & Weingartner 19xx for a review).
Included in this summary is the widely cited work of Flor-Henry on focal
epilepsy (N.Y. state health department). This work shows conclusively
that Manic depressive illness is associated with R-brain activation in
contrast to (Neurotic) Schizophrenia which is associated with L-brain activation;
in focal epilepsy. This is very strong evidence for the existence
of the two poles of a reformulated N-dimension. Of interest
here also is something that I recently heard from Paul Barrett to the effect
that M.W. Eysenck and Fahrnberg have recently uncovered some "disconcerting"
evidence that the N-dimension is in need of a major reassessment.
I haven't gotten the details of this, but given Hans Eysenck's rather dismal
report on the current state of experimental research on N:

"As regards the
N construct, the position is clearly unsatisfactory. We have to consider
the reasons why this might be so; perhaps future research, taking into
account the objections to current methodologies, will give more positive
results than are available at present."

(Eysenck 1990, Ch. 10, p. 270)

It seems quite likely
that N which was formulated some 50 years ago (Eysenck 1947), that it is
highly likely that Eysenck's classic N is only a "first approximation"
to True (bipolar) N. So o.k.,
there it is, the final step in the process; relating B/M and Sperry to
E-I and N. As I say the connection between B/M and E-I is quite strong
(vis a vis Stelmack). The evidence connecting N with Sperrian Lateralization
is certainly; new, but even that has not gone unsuspected. On p.
266 of Eysenck's 1990 Handbook of Personality article he devotes a paragraph
to the work of Lolas (1987) who has detected a "lateralized EEG result"
which correlates strongly with N, and has also surmised on the basis of
this that N is caused by Sperrian Lateralization! Well then,
with the experimental identification of B/M and Sperry with E-I and N,
we have finally arrived at the "Cartesian structure of Psychometric space"
(i.e. we refer to Eysenck's E,N,P as "Cartesian" because they are linearly
independent, and we now see that this linear independence does originate
in geometrical orthogonality of the B/M and Sperrian divisions of the brain). We of course
haven't mentioned "P" so far, but lets face it, if we prove that the brain
has 3-axes and 2 of them cause E and N, it's 66 2/3 % sure that the 3rd
axis is causing P! There is
in fact little if any experimental evidence proving this, but that is not
surprising considering that even Eysenck has yet to propose any definitive
biological (at least neuropsychological) basis for P. His 1967 biological
model you will recall only explains E and N. Eysenck says (ibid 1990
p. 270):

"Regarding the P
dimension...... What is clearly needed in this field is some more inclusive
theory.."

In line with
that suggestion, we see that according to the Cartesian Theory it is now
evident that P is associated with the "cephalization gradient" along the
neuraxis itself. This simply because there are 3 and only 3 primary
orthogonal cleavages of the egg (the 1st 3). If the first causes
N and the 2nd causes E-I, it would follow that the third simply causes
P. This is supported by the fact that the 3rd cleavage (and all subsequent
cleavages parallel or isomorphic to it) account for the somites of the
embryological body; including the vertebrae, the ribs, and the cephalic
neuromeres (segmentation of the cephalic end of the neural tube) which
is the morphological origin of the "diencephalon, mesencephalon and telencephalon".
It is surmised then (not to say intuitively obvious) that the "3rd cleavage"
causes a bipolar cephalization gradient, say stem-limbic-cortex; which
causes yet a 3rd bipolar neuropsychological dimension corresponding to
Eysenck's P. This, incidentally,
immediately tells us that Eysenck's P probably is suffering from the same
"absolute magnitude" problem as N! According to the Cartesian Theory,
all 3 dimensions in the Structural Model are strongly bipolar in precisely
the same sense that E-I is. This because all 3 dimensions originate
in 3 (nominally) identical biological mechanisms- namely the 3-primary
Cartesian cleavages of the egg! O.k., so
we have identified Mania (frustrated/sublimated emotion) as the missing
negative pole of N (+N still being classic hysteric/paranoid emotion; classic
Neurosis)- but what now could be the missing negative pole of Eysenck's
P? Well, just looking at the "cephalic gradient" from stem to cortex,
we see that we have a gradient from vegetative to intellectual (or in the
egg from vegetal to animal). Taking our que from the fact that "psychotics"
(especially the classic diabolical types) have a reputation for cleverness
and energy (consider the Unibomber for instance who entered Harvard on
full scholarship at the age of 16) we assume that +P must be at the cortical
end of the neuraxis. This means the missing negative pole of P must
lie at the lower end of the brain; the limbic to brainstem level... we
are looking then for the virtual human vegetable. This immediately
suggests Mental Retardation (MR) as the missing negative pole of Eysenck's
P dimension! Now all I
can do with respect to P, other than suggest that someone write a revised
bipolar questionnaire for P and factor analyze it with EPQ-N and EPQ-E
and see if it substantially increases the variance explained (i.e. produces
a much more robust P)... is to note the following piece of relevant evidence. The DSM-IV
has adopted a "two-category classification of all mental illness".
These two categories are called AXIS-I and AXIS-II (axis here simply means
category). AXIS-I contains all of the "florid mental disturbances"
namely the acute psychoses. Now this I say is suggestive of "+P".
AXIS-II contains mainly MR with the inclusion of long term mild dependency
disorders referred to as "Personality Disorders". The main clinical
features of these Personality Disorders seem to be things like "learned
helplessness, dependency, etc.". AXIS-II therefore, since it contains
all of the MR cases, I suggest is simply Eysenck's missing negative pole;
"-P". Thus the DSM-IV itself provides an immediate "bipolar reformulation"
of Eysenck's P. What we see is that 50 years of experience by the
World Health Organization has come to the same conclusion that Eysenck
has; that all mental illness is classified first and foremost according
to its location on the "Psychosis" dimension. The WHO however, having
a much larger empirical base than Eysenck has apparently identified both
poles of the dimension. Neuropsychologically
then, the Cartesian Theory indicates that (classic) Psychosis is caused
by an (abnormal) cortical shift and that -P, classic MR and dependency
disorders, are caused by just the opposite.. a lower brain stem shift.
Experimental research then would be looking for cortical vs. lower brain
activations correlating with a psychometric scale running from "pathological
dependency to pathological autonomy" or "MR to Psychotic" in clinical terms.
This would be True-P now running from -P to +P with normal in the middle.

O.k. then,
that completes an outline of the full story and explanation of:

Now, needless
to say this letter as long as it is, is but a brief outline of the full
detail of this theory. I have had to resort to illustration and heuristic
devices in this letter in order to condense the story to something manageable.
A rigorous and detailed treatment would require a book or a dozen papers
with 1,000 bibliographic citations from half a dozen scientific disciplines.
Numerous supporting studies have not even been mentioned. The Cartesian
Theory for instance explains theoretically the existence of "simple structure"
empirically discovered by Thurstone in 1935 and to this day still a theoretical
enigma. I have not
mentioned Gray's theory, even though my published paper (Hammond 1994)
is subtitled Unification of Eysenck and Gray. Nor have I mentioned
the Big-5 and Cattell's second order factors -all immediately explained
by the Cartesian Theory (The Big-5 is the subject of my Montreal address;
audio tape enclosed). Hopefully we can get to a discussion of these
results once we get the (considerable) challenge of reaching a conclusion
on the basic scientific bona fides addressed in this letter.

In closing
this letter let me say that I think our discussions may present a very
unique opportunity regarding this scientific theory. As I have mentioned
I have already had a somewhat comprehensive discussion of this theory with
Paul Barrett on Idanet. Unfortunately that was a public discussion
and not a private one. One cannot of course conduct a state of the
art and forensic scientific discussion in public. This simply because
public matters take precedent and science (especially professional level
topics) become secondary. Our discussion
however, is private and purely scientific and taking place in the venue
of competent academic discourse (as opposed to public discourse).
This will be an absolute first for the Cartesian Theory. As I say
I have also discussed this theory briefly with Hans Eysenck, again however
that was at an international Psychology congress and again was more of
a public policy sensitive discussion than a technical one. I am hopeful
that a young Ph.D. like yourself, obviously of superior academic/research
achievement who might still have the time and the inclination to make a
purely academic/scientific assessment of this question, will be able to
provide not only me, but other more beleaguered scientists like Hans Eysenck,
Jeffrey Gray, M.W. Eysenck, Paul Barrett and many others with a purely
formal, academic assessment of this theory, according to the contemporary
standards of formal academic research in Personality. That inquiry
and that judgement is what the senior people need before they can even
consider how this new piece of the puzzle might fit into the larger currents
in Psychology research. I suggest
we move methodically at whatever speed we can muster given the eternal
restraints on time and resources; in this direction.

In the meantime
I have studied your 3 1995 papers with Jeffrey Gray, Glenn Wilson et al.
and I am gratified and immensely relieved to find that they are of the
highest order of formal academic research, flawlessly and powerfully conducted
and expressed. I therefore have unqualified confidence in your scientific
judgement and will not have to spend time negotiating around any major
scientific deficiencies on your part- after studying these papers at length
I find none.

Finally, I'm
sorry I've taken so long in responding, as I have other demands on my time.
I expect that you likewise are busy and I don't expect a reply from you
right away. I am presently
working on several papers at once, one of which will contain some of the
material contained in this letter. At the rate I'm going I probably
won't have them ready until next spring.

I am looking
forward to hearing from you, and I would appreciate it if you could email
me a short note when you receive this letter just so I will know that you
have received the materials.